How to Grow Cucumbers From Seed

cucumber seedlings in a pot

The Spruce / Margot Cavin

Project Overview
  • Total Time: 7 wks, 1 day - 10 wks
  • Skill Level: Kid-friendly

There's nothing quite as satisfying as the crunch of a fresh, cool cucumber on a hot summer day. They are good for snacks, salads, and even skincare. Cucumbers also can be added to water for light flavoring. And when the summer comes to a close, you can pickle the rest of the harvest to enjoy all year long. Although cucumbers can run into issues with pests, they are still pretty easy to grow from seed. Most varieties are ready for harvesting in 50 to 70 days.

Here's how to start cucumbers from seed for your garden.

What You'll Need

Equipment / Tools

  • Trowel
  • Watering can/hose
  • Knife/pruners
  • Pest/disease remedies (as needed)


  • Cucumber seeds
  • Fertilizer and/or compost
  • Support structure (optional)
  • Mulch


  1. Plant the Seeds

    Cucumbers are traditionally planted in rows or mounds. You'll find bush varieties, as well as vining cucumbers. Bush varieties don't need staking, but they can take up a lot of garden space. Often, vining cucumbers are allowed to sprawl along the ground. However, when they sprawl on the ground, they're more susceptible to disease and pests, plus they take up prime garden real-estate.. Instead, train vining cucumbers to climb a fence, trellis, or other sturdy support structure for a more contained growing site.

    Wait until the soil has warmed to around 70 degrees Fahrenheit before planting your seeds. Pick a site that gets lots of sun and has rich, well-draining soil with a slightly acidic to neutral soil pH. Seeds also can be started indoors about a month before your area's last projected frost date in the spring. 

    Plant seeds 1 inch deep. Make sure you know which type of cucumber you're planting: bush or vining. While spacing largely depends on variety, here are some general estimates:

    • For rows: Plant seeds around 4 to 6 inches apart in rows that are 3 to 5 feet apart.
    • For mounds: Create small hills that are around 1 to 1.5 feet in diameter and a few inches high, spacing mounds 1 to 2 feet apart, and plant two to three seeds per mound.
    • For support structures: Plant two to three seeds per foot. 
    planting cucumber seeds

    The Spruce / K. Dave

  2. Thin the Seedlings

    Germination generally takes between three and 10 days. Cooler temperatures can slow the process, and temperatures below 50 degrees Fahrenheit will likely prevent germination.

    Once the seedlings are around 4 inches tall, it's time to thin them. Use pruners to snip the seedlings off at their base rather than pulling them, as pulling can disturb roots of the plants you're keeping. Add mulch around the plants to retain soil moisture.

    • For rows: Thin seedlings to approximately 1 to 1.5 feet apart.
    • For mounds: Remove all but the strongest seedling in each mound.
    • For support structures: Thin seedlings to around a foot apart.
    cucumber seedlings

    The Spruce / K. Dave

  3. Tend to the Plants

    Aim to keep the soil evenly moist but not waterlogged. Around an inch of water per week is fine, but plan to water more in hot weather. Avoid an irregular watering schedule, as this can result in oddly shaped and bitter cucumbers. Try to keep the foliage dry when you water to help prevent fungal diseases. 

    Use either an organic liquid or slow-release granule fertilizer that's made for vegetables at the time of planting and then throughout the growing season, following label instructions. You can also side-dress with some compost to boost growth.

    cucumber seedlings

    The Spruce / K. Dave

  4. Watch Out for Pests and Diseases

    As the growing season progresses, your cucumber plants will attract beneficial insects like bees that aid in pollination and subsequent fruit production. But they also might bring in some pests and diseases. The cucumber beetle is the most likely pest to target your crop. Parasitic nematodes can help curb them, as well as simply picking them off. Tansies are thought to deter cucumber beetles, too, so they could be worth planting by your cucumber crop.

    Choosing a good variety also can help to prevent pests and diseases. Asian cucumbers, for example, are more disease resistant than larger varieties. 'Straight Eight' is resistant to the mosaic virus, a common cucumber malady. And 'Tasty Jade' grows well on a trellis, saving space in the garden.

    Another major key to avoid pests and diseases lies in crop rotation. If you have pest-attracting gourds in the same place season after season, they will be prone to problems. Try to plant cucumbers after spinach or legumes, and follow them with a nitrogen-fixing ground cover, such as clover, during the winter.

    cucumber preparing to fruit
    ​The Spruce / Margot Cavin
  5. Harvest

    Note the mature size of your cucumber variety, as this can range from around 3 to 8 inches on average. Harvest as soon as they reach this mature size. Letting them continue to grow will adversely affect flavor and quality. Plus, if just one cucumber grows long enough that the seeds mature, the entire plant will stop producing cucumbers. 

    Check the vines daily for harvestable cucumbers. Use a knife or pruners to cut the stem, as pulling them off can damage the vine. Cucumbers will keep in the refrigerator wrapped in plastic for a little over a week. 

    cucumbers ready for harvest

    The Spruce / K. Dave